I have a very similar setup only the oil filter is down low.... tried to prime the cooler but could only get a bit under 500ml in there with everything connected (feeding using funnel into dash10 braid not fun). I'm thinking crank it for a few seconds (no fuel) till I get oil pressure then start it normally. Im fairly sure the oil filter being so low self primes on mine though, well it filled with oil when I filled the sump anyway. Yet to start it though, waiting on ecu (also an sm4).
btw your engine looks very similar to mine